Moisture eliminator with regenerative purge cycle

ABSTRACT

A vehicle leveling system having an inlet cartridge with dessicant means therein for removing moisture from atmospheric air during a pump-up phase of operation wherein a compressor operated only in response to vehicle operation draws air from atmosphere through the dessicant means to remove moisture therefrom. During an exhaust phase of operation when the vehicle is stopped, the compressor no longer draws air through the dessicant means, the air is exhausted from the pressurized system back through the dessicant means for removing moisture therefrom. A vehicle component is located closely adjacent the cartridge for changing the temperature thereof from a reduced temperature during the intake phase of operation and to an elevated temperature at the exhaust phase of operation to provide an effective high temperature regenerative purge of the dessicant means during exhaust from the pressurized system when the vehicle is stopped.

llnited States Patent 1191 Wanner Jan.8,1974

[ MOISTURE ELWINATOR WITH REGENERATIVE PURGE CYCLE [75] Inventor:

[73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Nov. 17, 1972 [21] Appl. No.: 307,217

Joseph W. Wanner, Kettering, Ohio Primary Examiner-Philip Goodman Attorney-Sidney Carter et a].

[57] ABSTRACT A vehicle leveling system having an inlet cartridge with dessicant means therein for removing moisture from atmospheric air during a pump-up phase of operation wherein a compressor operated only in response to vehicle operation draws air from atmosphere through the dessicant means to remove moisture therefrom. During an exhaust phase of operation when the vehicle is stopped, the compressor no longer draws air through the dessicant means, the air is exhausted from the pressurized system back through the dessicant means for removing moisture therefrom. A vehicle component is located closely adjacent the cartridge for changing the temperature thereof from a reduced temperature during the intake phase of operation and to an elevated temperature at the exhaust phase of operation to provide an effective high temperature regenerative purge of the dessicant means during exhaust from the pressurized system when the vehicle is stopped.

3 Claims, 1 Drawing Figure 1 MOISTURE ELIMINATOR WITH REGENERATIVE PURGE CYCLE This invention relates to auxiliary pressure systems on motor vehicles using ambient air as the pressurizable medium and more particularly to air dryers for use in auxiliary pressurized air systems for motor vehicles.

Compressed air systems on vehicles often depend on atmospheric inlets to provide make-up air for use in the systems. Intake air can be relatively humid depending upon the ambient conditions around the vehicle. in such cases, substantial amounts of moisture can be condensed in the system.

Accordingly, such systems often include a provision for removing moisture from the intake air during system operation. One approach has been to provide a condenser in the inlet line of the system for removing moisture therefrom. in such arrangements, the trapped moisture is periodically removed from the condenser by elaborate valving arrangements. In other arrangements, separate heaters are provided on the moisture removing means for increasing the temperature of the moisture removing means during a purge cycle of operation for removing moisture therefrom.

An object of the present invention is to improve the removal of moisture from intake air to a compressed air system for use on motor vehicles without requiring elaborate valving arrangements or the provision of separate heater means operated during a purge cycle of operation by combining a cartridge having dessicant means therein in combination with an existing vehicle component which is operated to have a low temperature at vehicle startup and an elevated temperature following vehicle operation, so that removal of moisture by the dessicant means is accomplished under a reduced temperature and purge therefrom is accomplished under an elevated temperature solely in response to temperature change produced by operation of the vehicle component.

Another object of the present invention is to provide an improved pressurized air system for use on a motor vehicle including an air intake system operative during a pump-up phase of operation which includes a cartridge located closely adjacent a vehicle component which is operated from a reduced temperature at vehicle startup to an elevated temperature following vehicle operation and includingdessicant means therein following the temperature of the vehicle component and wherein a compressor is operated only in response to vehicle operation to draw air through the cartridge during a pump-up phase of operation for removing moisture from the intake air and wherein means including the compressor operate when the vehicle is stopped to exhaust it back through the-dessicant means which is heated by the vehicle component to an elevated temperature to produce an effective purge of moisture from the dessicent means during an exhaust phase of operation when the vehicle is stopped.

Still another object of the present invention is to provide an improved vehicle leveling system including air spring means for producing an uplifting force to level a vehicle, the spring being inflated by a compressor which is operated only in response to vehicle operation and wherein inlet air to the compressor is supplied from an air vent through dessicant means within a cartridge which arenormally cold when the vehicle is initially started and which is heated by a vehicle component which increases in temperature in response to vehicle operation and wherein a regenerative purge cycle through the dessicant means is initiated when the vehicle component has heated the cartridge, the vehicle is unloaded and the compressor means is stopped.

These and other objects of the present invention are attained in one working embodiment which includes a moisture eliminator cartridge securely housing a quantity of absorbent material which removes moisture from cold, humid inlet air during a pump-up phase of operation. The cartridge is located closely adjacent the engine of the vehicle to be heated thereby. The engine upon vehicle startup is normally cold whereby air drawn through the cartridge has moisture therein removed by the dessicant means. A compressor operated by the engine serves to draw air through the cartridge and the dessicant means therein only when the vehicle is operated. During this phase the engine is relatively cool so that moisture is deposited in the dessicant means at a reduced temperature level. The dried air is directed from the compressor to an air spring means for leveling the vehicle. v

During vehicle operation, the engine heats the cartridge and air to an elevated temperature. The system includes valve means for communicating the air spring means with the cartridge and when the vehicle is stopped, the compressor will block flow from the cartridge to the air spring means to cause counterflow of air through the cartridge. Exhaust air flow from the air spring means produces an effective counterflow regenerative purging of moisture from the adsorbent to be returned to atmosphere and thereby removed from the system.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

The single FIGURE is a schematic view of a system including a vertical sectional view of an intake cartridge of the present invention.

It includes a. moisture eliminator assembly 10 which is operatively located adjacent the engine 12 of a vehicle. A compressor 14 is driven directly off the engine 12 to compress air only during vehicle operation. This air is supplied to a pair of auxiliary load supporting air spring and shock absorber units l6, 18.

The moisture eliminator assembly 10 more particularly includes a tubular cartridge 20 having an upper open end closed by a dome 22 with an inlet 24 thereon in which is threadably received an inlet fitting 26 that is secured to one end of an air vent line 28. An eight to 10 pound coil spring 30 is located within the dome 22 having one of its ends in engagement with the dome 22 and having the opposite end thereof carried by a 20 mesh perforated plate 32. The plate 32 is supported against a quarter inch felt pad 34 that serves to filter gas flow therethrough and retain particles 36 of a suitable dessicant such as activated alumina or silica type adsorbent or a Linde type molecular sieve material 0.4 lb. mol.

The particles 36 fill the cartridge 22. An open end at the base thereof is closed by a felt pad 38 supported by a perforated plate 40 of 20 mesh. The plate 40 is located above a lower dome 42 which forms a bypass chamber 44 at the lower end of the moisture eliminator assembly 10. The chamber 44 has a first port 46 therein in communication with a fitting 48 welded thereto which in turn is fluidly connected to a conduit 50 which connects to an inlet 52 of the compressor 14. An outlet 54 from the compressor is connected to a supply conduit 56 which is fluidly connected to an inlet fitting 58 on the side of a tube 60 of an air spring 62 on the unit 18. The air spring is further comprised of a resilient sleeve 64 fastened by means of a clamp ring 66 to the tube 60. They form a pressurizable air chamber 68. A fitting 70 on the unit 18 communicates the pressurizable chamber 68 thereof through a crossover conduit 72 with a fitting 74 on the unit 16 which corresponds to the fitting 58. The air spring on unit 16 includes components like those found in the unit 18.

A height responsive valve assembly 76 is located on the unit 16 at the outlet thereof to control pressure within the unit 16, 18 for leveling the vehicle. It is of the type shown in U.S. Pat. No. 3,666,287, issued May 10, 1972, to Joseph W. Wanner. It includes an outlet 78 therefrom which is connected to a conduit 80 having the opposite end thereof connected to a fitting 82 welded to the lower dome 42 at a port 84 therein in communication with the bypass chamber 44.

In accordance with certain principles of the present invention, the moisture eliminator functions to remove moisture from humid inlet air thereby to prevent it from entering the system to effect the operation of the system. More particularly, when the vehicle is initially started the engine 12 is cold and the compressor 14 will be operated therefrom to draw air from atmosphere through the inlet line 28. Any moisture in the humid outside air is deposited on the adsorbent particles 36 and the air is thence drawn through the chamber 44, fitting 48 and conduit 50 to the inlet of the compressor 52. The air is discharged under pressure and directed through the supply conduit 56 into the pressurizable chambers of the units l6, 18. The valve 76 is closed to trap air in the units 16, 18. Following a predetermined pump-up period of operation the units will be inflated to a level to produce a supplemental uplifting force to level the vehicle. Once the vehicle is level, the valve 76 will bleed air through the conduit 80 thence the fitting 82 and the chamber 44 back through the fitting 48 to the inlet 52 of the compressor. This constitutes a normal phase of operation wherein air is continually bypassed through the chamber 44 and during this period, no humid air is directed through the dessicant particles 36.

During system operation, the vehicle engine 12 is increasing in temperature to raise the temperature of the cartridge 12 and the bypass space 44 and air being circulated therein. Thus, the air in the system is continually increased in temperature to follow the temperature increases of the engine 12 to a normal equilibrium temperature in the order of 300 350 F. The starting temperature of the unit would be comparable to ambient air conditions during the pump-up phase. Thus, there is a substantial temperature difference between the intake air directed through the dessicant cartridge 36 during the pump-up phase at which moisture is deposited on the dessicant cartridge and the temperature of air circulated through the illustrated system during normal Operation. This temperature differential is utilized to produce an effective regenerative action on the adsorbent column within the cartridge during a counterflow phase of operation which is instituted when the vehicle is stopped and unloaded.

More particularly, when the vehicle is stopped the compressor 14 blocks communication between the conduit 50 and conduit 56. Concurrently, when the vehicle is unloaded, the valve 76 is conditioned to open the pressurizable chamber 68 to the exhaust conduit and air will then pass from the units 16, 18 into the bypass chamber 44. Since the compressor 14 is no longer operated and it blocks communication between the conduits 50, 56 air flow at the elevated temperature established by the operating vehicle component, represented by the engine 12, will counterflow through the adsorbent particles 36 to be discharged through the vent line 28 to atmosphere. Since the air temperature in the system has been elevated by the working vehicle component represented by the engine 12, it will constitute a high temperature medium for driving moisture from the adsorbent particles 36 and be carried by the counterflow of air through the column 36 outwardly of the system to produce an effective purge cycle of operation.

While the embodiments of the present invention, as herein disclosed, constitute a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. An air supply dryer system comprising a cartridge having an inlet in communication with atmosphere and an outlet, dessicant means within said cartridge located between said inlet and outlet for removing moisture from air directed therethrough, means forming a bypass chamber in communication with said outlet, a vehicle component located closely adjacent said cartridge having a low initial temperature at vehicle startup and an elevated temperature following vehicle operation, compressor means having an inlet and an outlet, means fluidly connecting said compressor means inlet to said cartridge outlet, air spring means including an inlet and an outlet, means fluidly connecting the compressor outlet to the inlet of said air spring means and the outlet of said air spring means to said bypass chamber on said cartridge, means for operating said compressor only in response to vehicle operation for drawing cold, moist air through said cartridge inlet thence through said dessicant means for drying said cold air when the vehicle component is at initial vehicle startup temperature, height responsive valve means for controlling air flow from atmosphere through said dessicant means during inflation of said air spring means at initial vehicle startup, said compressor following inflation of said air springs drawing air through a fluid circuit including said air spring means and said cartridge bypass chamber, said vehicle component increasing in temperature as said vehicle is operated and heating said closely adjacent located cartridge and the dessicant means therein, said compressor means being inoperative when the vehicle is stopped and said height responsive valve means being conditioned when the vehicle is unloaded to cause exhaust of air from said air spring means through said cartridge from said bypass chamber to said cartridge inlet, said vehicle component heated cartridge warming the exhaust air from said air spring means to a temperature elevated with reference to that of air drawn from atmosphere through said cartridge during inflation of said air spring means to produce an elevated temperature medium for purging moisture buildup in said dessicant means for discharge through said cartridge inlet during the exhaust phase of operation.

2. A vehicle leveling system comprising an air inlet cartridge having an inlet and an outlet, a compressor having an inlet connected to said cartridge outlet and having an outlet therefrom, air spring means having an inlet, means fluidly connecting said air spring means inlet to said compressor outlet, an outlet from said air spring means, means for fluidly communicating said air spring means outlet with said cartridge, a vehicle component having a low temperature at vehicle startup and an increasing temperature during vehicle operation, said vehicle component being located closely adjacent said cartridge for heating said cartridge, valve means having a first operative position upon vehicle startup and addition of load to the vehicle to cause air from said compressor means to be trapped within said air springs, said compressor means operating upon vehicle startup to draw air from said cartridge inlet therethrough for discharge into said air spring means for inflating said air spring means to support additional vehicle load, dessicant means located within said cartridge between said cartridge inlet and outlet having a reduced temperature at vehicle startup, said dessicant means removing moisture from said inlet air during inflation of said air spring means through a pump-up phase of operation, said cartridge including a bypass chamber in communication with said cartridge outlet heated by said vehicle component for directing air from said air springs to said compressor for return to said air spring means during normal vehicle operation, said valve means having a second operative position to communicate said air spring means with said cartridge during a normal phase of operation wherein said compressor means is operated during vehicle operation, said compressor means serving to block communication between said cartridge outlet and said air spring means inlet when the vehicle is stopped, said valve means and said bypass chamber serving to direct exhaust air from said air spring means through said dessicant means outwardly of said cartridge inlet during an exhaust phase of operation when the vehicle is stopped and unloaded, said vehicle component heating the cartridge and the air passing through said bypass chamber therein to cause the temperature of the air during exhaust to be elevated with respect to the temperature of the air drawn into the cartridge during the pump-up phase of operation whereby moisture removed from the inlet air by the dessicant means during the pump-up phase of operation is effectively purged therefrom by a higher temperature purge stream during the exhaust phase of operation.

3. A vehicle leveling system comprising an air inlet cartridge having an inlet and an outlet, a compressor having an inlet connected to said cartridge outlet and having an outlet therefrom, air spring means having an inlet, means fluidly connecting said air spring means inlet to said compressor outlet, an outlet from said air spring means, means for fluidly communicating said air spring means outlet with said cartridge, a vehicle en gine having a low temperature at vehicle startup and an increasing temperature during vehicle operation, said vehicle engine being located closely adjacent said cartridge for heating said cartridge, valve means having a first operative position upon vehicle startup and addition of load to the vehicle to cause air from said compressor means to be trapped within said air springs, said compressor means including means operated by said engine upon vehicle startup to draw air from said cartridge inlet therethrough for discharge into said air spring means for inflating said air spring means to support additional vehicle load, dessicant means located within said cartridge between said cartridge inlet and outlet having a reduced temperature at vehicle startup, said dessicant means removing moisture from said inlet air during inflation of said air spring means through a pump-up phase of operation, said cartridge including a bypass chamber in communication with said cartridge outlet heated by said vehicle component for directing air from said air springs to said compressor for return to said air spring means during normal vehicle operation, said valve means having a second operative position to communication said air spring means with said cartridge during a normal phase of operation wherein said compressor means is operated during vehicle operation, said compressor means serving to block communication between said cartridge outlet and said air spring means inlet when the vehicle is stopped, said valve means and said bypass chamber serving to direct exhaust air from said air spring means through said dessicant means outwardly of said cartridge inlet during an exhaust phase of operation when the vehicle is stopped and unloaded, said vehicle component heating the cartridge and the air passing through said bypass chamber therein to cause the temperature of the air during exhaust to be elevated with respect to the temperature of the air drawn into the cartridge during the pump-up phase of operation whereby moisture removed from the inlet air by the dessicant means during the pump-up phase of operation is effectively purged therefrom by a higher temperature purge stream during the exhaust phase of operation. 

1. An air supply dryer system comprising a cartridge having an inlet in communication with atmosphere and an outlet, dessicant means within said cartridge located between said inlet and outlet for removing moisture from air directed therethrough, means forming a bypass chamber in communication with said outlet, a vehicle component located closely adjacent said cartridge having a low initial temperature at vehicle startup and an elevated temperature following vehicle operation, compressor means having an inlet and an outlet, means fluidly connecting said compressor means inlet to said cartridge outlet, air spring means including an inlet and an outlet, means fluidly connecting the compressor outlet to the inlet of said air spring means and the outlet of said air spring means to said bypass chamber on said cartridge, means for operating said compressor only in response to vehicle operation for drawing cold, moist air through said cartridge inlet thence through said dessicant means for drying said cold air when the vehicle component is at initial vehicle startup temperature, height responsive valve means for controlling air flow from atmosphere through said dessicant means during inflation of said air spring means at initial vehicle startup, said compressor following inflation of said air springs drawing air through a fluid circuit including said air spring means and said cartridge bypass chamber, said vehicle component increasing in temperature as said vehicle is operated and heating said closely adjacent located cartridge and the dessicant means therein, said compressor means being inoperative when the vehicle is stopped and said height responsive valve means being conditioned when the vehicle is unloaded to cause exhaust of air from said air spring means through said cartridge from said bypass chamber to said cartridge inlet, said vehicle component heated cartridge warming the exhaust air from said air spring means to a temperature elevated with reference to that of air drawn from atmosphere through said cartridge during inflation of said air spring means to produce an elevated temperature medium for purging moisture buildup in said dessicant means for discharge through said cartridge inlet during the exhaust phase of operation.
 2. A vehicle leveling system comprising an air inlet cartridge having an inlet and an outlet, a compressor having an inlet connected to said cartridge outlet and having an outlet therefrom, air spring means having an inlet, means fluidly connecting said air spring means inlet to said compressor outlet, an outlet from said air spring means, means for fluidly communicating said air spring means outlet with said cartridge, a vehicle component having a low temperature at vehicle startup and an increasing temperature during vehicle operation, said vehicle component being located closely adjacent said cartridge for heating said cartridge, valve means having a first operative position upon vehicle startup and addition of load to the vehicle to cause air from said compressor means to be trapped within said air spriNgs, said compressor means operating upon vehicle startup to draw air from said cartridge inlet therethrough for discharge into said air spring means for inflating said air spring means to support additional vehicle load, dessicant means located within said cartridge between said cartridge inlet and outlet having a reduced temperature at vehicle startup, said dessicant means removing moisture from said inlet air during inflation of said air spring means through a pump-up phase of operation, said cartridge including a bypass chamber in communication with said cartridge outlet heated by said vehicle component for directing air from said air springs to said compressor for return to said air spring means during normal vehicle operation, said valve means having a second operative position to communicate said air spring means with said cartridge during a normal phase of operation wherein said compressor means is operated during vehicle operation, said compressor means serving to block communication between said cartridge outlet and said air spring means inlet when the vehicle is stopped, said valve means and said bypass chamber serving to direct exhaust air from said air spring means through said dessicant means outwardly of said cartridge inlet during an exhaust phase of operation when the vehicle is stopped and unloaded, said vehicle component heating the cartridge and the air passing through said bypass chamber therein to cause the temperature of the air during exhaust to be elevated with respect to the temperature of the air drawn into the cartridge during the pump-up phase of operation whereby moisture removed from the inlet air by the dessicant means during the pump-up phase of operation is effectively purged therefrom by a higher temperature purge stream during the exhaust phase of operation.
 3. A vehicle leveling system comprising an air inlet cartridge having an inlet and an outlet, a compressor having an inlet connected to said cartridge outlet and having an outlet therefrom, air spring means having an inlet, means fluidly connecting said air spring means inlet to said compressor outlet, an outlet from said air spring means, means for fluidly communicating said air spring means outlet with said cartridge, a vehicle engine having a low temperature at vehicle startup and an increasing temperature during vehicle operation, said vehicle engine being located closely adjacent said cartridge for heating said cartridge, valve means having a first operative position upon vehicle startup and addition of load to the vehicle to cause air from said compressor means to be trapped within said air springs, said compressor means including means operated by said engine upon vehicle startup to draw air from said cartridge inlet therethrough for discharge into said air spring means for inflating said air spring means to support additional vehicle load, dessicant means located within said cartridge between said cartridge inlet and outlet having a reduced temperature at vehicle startup, said dessicant means removing moisture from said inlet air during inflation of said air spring means through a pump-up phase of operation, said cartridge including a bypass chamber in communication with said cartridge outlet heated by said vehicle component for directing air from said air springs to said compressor for return to said air spring means during normal vehicle operation, said valve means having a second operative position to communication said air spring means with said cartridge during a normal phase of operation wherein said compressor means is operated during vehicle operation, said compressor means serving to block communication between said cartridge outlet and said air spring means inlet when the vehicle is stopped, said valve means and said bypass chamber serving to direct exhaust air from said air spring means through said dessicant means outwardly of said cartridge inlet during an exhaust phase of operation when the vehicle is stopped and unloaded, said vehicle component heating the cartridge And the air passing through said bypass chamber therein to cause the temperature of the air during exhaust to be elevated with respect to the temperature of the air drawn into the cartridge during the pump-up phase of operation whereby moisture removed from the inlet air by the dessicant means during the pump-up phase of operation is effectively purged therefrom by a higher temperature purge stream during the exhaust phase of operation. 